Changeset 11682

Timestamp:

12/14/14 01:02:09 (10 years ago)

Author:

swagner

Message:

#2205: Worked on cancellation

• added throwing of OperationCanceledException in MessagePort.ReceiveMessage
• tweaked AlgorithmNode to get rid of exceptions when the algorithm is aborted

Location:

branches/OptimizationNetworks

Files:

• HeuristicLab.Core/3.3/Networks/MessagePort.cs (modified) (1 diff)
• HeuristicLab.Networks/3.3/AlgorithmNode.cs (modified) (4 diffs)

branches/OptimizationNetworks/HeuristicLab.Core/3.3/Networks/MessagePort.cs

@@ -182 +182 @@
       LastMessage = message;
       OnMessageReceived(message, token);
+      token.ThrowIfCancellationRequested();
     }
     public event EventHandler<EventArgs<IMessage, CancellationToken>> MessageReceived;

branches/OptimizationNetworks/HeuristicLab.Networks/3.3/AlgorithmNode.cs

@@ -36 +36 @@
   public class AlgorithmNode : Node, IAlgorithmNode {
     private object locker = new object();
-    private Dictionary<IAlgorithm, AutoResetEvent> waitHandles = new Dictionary<IAlgorithm, AutoResetEvent>();
-    private Dictionary<IAlgorithm, Exception> exceptions = new Dictionary<IAlgorithm, Exception>();
 
     new public PortCollection Ports {
@@ -115 +113 @@
         }
         algorithm = (IAlgorithm)Algorithm.Clone(cloner);
-        waitHandles.Add(algorithm, new AutoResetEvent(false));
       }
 
@@ -131 +128 @@
       }
 
-      algorithm.StoreAlgorithmInEachRun = false;
-      algorithm.Prepare(true);
-      algorithm.ExceptionOccurred += Algorithm_ExceptionOccurred;
-      algorithm.Stopped += Algorithm_Stopped;
-
-      using (token.Register(() => { algorithm.Stop(); })) {
+      token.ThrowIfCancellationRequested();
+
+      Exception exception = null;
+      using (var started = new AutoResetEvent(false))
+      using (var stopped = new AutoResetEvent(false))
+      using (var ctr = token.Register(() => {
+        started.WaitOne();
+        try { algorithm.Stop(); }
+        catch (InvalidOperationException) {
+          // NOTE:
+          // After the algorithm's engine is stopped, all stateful items in the algorithm are cleared before the execution state of the algorithm is set to stopped.
+          // When algorithm.Stop() is called during that operation, an InvalidOperationException is thrown because Stop is called on the engine but the engine is already stopped.
+          // This exception can be ignored, as the algorithm will stop immediately after the clearing of its stateful items is finished.
+        }
+      })) {
+        algorithm.StoreAlgorithmInEachRun = false;
+        algorithm.Prepare(true);
+        algorithm.ExceptionOccurred += (sender, args) => { exception = args.Value; };
+        algorithm.Started += (sender, args) => { started.Set(); };
+        algorithm.Stopped += (sender, args) => { stopped.Set(); };
         algorithm.Start();
-        waitHandles[algorithm].WaitOne();
-      }
-
-      lock (locker) {
-        waitHandles[algorithm].Dispose();
-        waitHandles.Remove(algorithm);
-
-        Exception ex = null;
-        if (exceptions.TryGetValue(algorithm, out ex)) {
-          exceptions.Remove(algorithm);
-          throw ex;
-        }
-      }
+        stopped.WaitOne();
+      }
+
+      if (exception != null) throw exception;
+      token.ThrowIfCancellationRequested();
 
       // retrieve results
@@ -166 +169 @@
     }
 
-    private void Algorithm_ExceptionOccurred(object sender, EventArgs<Exception> e) {
-      var algorithm = (IAlgorithm)sender;
-      lock (locker) {
-        exceptions.Add(algorithm, e.Value);
-      }
-      algorithm.Stop();
-    }
-    private void Algorithm_Stopped(object sender, EventArgs e) {
-      lock (locker) {
-        waitHandles[(IAlgorithm)sender].Set();
-      }
-    }
-
     public event EventHandler AlgorithmChanged;
     protected virtual void OnAlgorithmChanged() {